Surface cleaning apparatus



Oct. 18, 1960 w. A. ARDITO SURFACE CLEANING APPARATUS Filed Sept. ll, 1958 -INVENTOR WlLLIAM ARDITO ATTORNEY SURFACE 'CLEANIN G APPARATUS A. Ardito, West Springfield, Mass., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Filed Sept. 11, USS, Ser. No. 760,398

Claims. (Cl. 15-41) This invention relates to surface cleaning apparatus, and more particularly to a device for readily converting a motorized floor polisher or scrubber to a carpet cleaning machine.

Conventional machines for polishing or scrubbing smooth floors of wood, linoleum, and the like, are equipped with one or more rotatable brushes or cleaning members which are arranged to be driven by an electric motor. When the machine is in use for scrubbing floors the brushes rotate in a generally horizontal plane, with their bristle tips movably contacting the floor surface. And, since the application of considerable brush pressure is required for thoroughly cleaning smooth surfaces, the brushes are arranged to support the Weight of the entire machine.

However, the brush pressure that is suitable for cleaning smooth floors is excessive for relatively rough-tex tured carpets, since the excessive sliding friction now obtained causes extreme wear on the rug and difficulty in maneuvering the machine. As is well known, there are two ways to correct this condition of excessive friction, to reduce the brush pressure and/ or to use smoother textured cleaning tools. Some prior art efforts have been directed toward reducing brush pressure by providing rolling or sliding support for the machine, thereby utilizing the effective cleaning action that only a brush can accomplish, but presenting the diflicult problem of providing inexpensive means to compensate automatically for brush wear and different pile thicknesses. Most of such prior devices provide manually adjustable means for properly positioning the brush with respect to the carpeted surface.

The present invention is of the type wherein the cleaning members are partly converted to smooth-surface cleaning members, but they continue to support the weight of the machine. For each of the brushes there is provided a smooth, apertured plate, preferably discshaped, and means for attaching the plate to the brush so that the plate is movable relative the brush along a common axis of rotation. Spring means are also provided to bias one broad surface of the plate into engagement with the tips of the brush bristles.

By this arrangement, all the bristles carry the Weight of the machine; some of the bristles being exposed at the apertures of the plate for cleaning the rug and establishing a driving connection with the plate at marginal portions of the apertures. Other bristles bear resiliently against the upper surface of the plate and transmit some of the weight of the machine to the floor therethrough, thus reducing sliding friction and accomplishing resilient resistance to rocking movement of the plate. Furthermore, the means by which the plate is attached to the brush self-compensates for brush wear and varying thicknesses of carpet pile.

The various objects, features and advantages of the present invention will appear more fully from the detailed description which follows, taken in connection with nited States Patent the accompanying drawings, forming a part of this application, in which:

Fig. 1 is a front elevational view of a floor polisher head, partly broken away and partly in section, illustrating the attachment device constructed and attached thereto according to the invention.

Fig. 2 is an enlarged view of the brush and attachment device shown in vertical section in Fig. 1;

Fig. 3 is a top view of the device, constructed in accordance with the invention; and

Fig. 4 is an elevational view of the device of Fig. 3.

The invention, as shown in the drawings, is applied to a twin brush polishing machine. However, it is equally applicable to ambulant surface cleaning apparatus having one or more brushes.

The machine of Fig. 1 comprises a frame 10 which supports an electric motor 12, which in turn is connected through suitable gearing, not illustrated, to a pair of vertical drive shafts 14. Attached at the lower end of the drive shafts 14 and arranged, respectively, to be driven thereby are a pair of scrubbing brushes 16 which rotate about vertical axes, in a plane parallel to the surface being cleaned. The brushes 16 include a rigid back portion 18 in which are secured a multiplicity of bristles 20. In operating position, the bristles 20 extend downwardly and radially outwardly, supporting the entire weight of the machine and transmitting it to the carpeted surface.

The weight of the machine is supported on the brushes 16 so that the normal brush pressure required for thoroughly cleaning smooth floors does not have to be produced by operator effort. Sliding friction must be established when cleaning is done by agitation; and, as is well known, the amount of friction obtained is determined by the texture or condition of the sliding surfaces and the force pressing them together.

Excessive sliding friction is encountered when motorized floor scrubbers, of the type set forth, are used for cleaning carpets. The normal force required to obtain suflicient sliding friction for cleaning smooth floors proves excessive for cleaning relatively rough-textured carpets. Even when a wet or dry cleaning substance is applied to the carpets, its lubricating effect is insuflicient to reduce sliding friction to acceptable levels. Excessive friction interferes with the free and easy movement of the machine over the carpeted surface and subjects both the carpet and the bristles of the scrubbing brush to undue wear.

In order to reduce the sliding friction between the bristles 20 of each brush 16 and the carpeted surface, a device 22 for each brush 16 is provided which is attachable to the working side thereof and in coaxial relationship therewith. According to the invention, the device 22 comprises a circular plate or disc 24 having a smooth, carpet-contacting surface. Formed in the disc 24 are a plurality of apertures 26 which are spaced apart equally and arranged in an annular series about the common rotational axis of the disc and brush. Marginal edge portions of the disc 24 and apertures 26 are preferably turned up to ensure that no sharp edges will come into damaging contact with the carpet.

For securing the disc 24 and brush 16 together, each is provided with one of the cooperating elements of a snap fastener. As best seen in Fig. 2, the upper element 28 of the snap fastener is rigidly carried by a centrally located, depending portion of the brush 16. The other or lower element 30 of the snap fastener is rigidly secured to the horizontal member 34 of a carriage, the member 34 being slidable on a pair of upright pins 36 which extend through a pair of openings in the member 34. In turn, the pins 36 are suitably anchored to the disc 24 and each has a head 38 at the upper end thereof. The arrangement is such that when the snap fastener elements 28 and 30 are engaged, the disc 24 is loosely and concentrically connected to the brush 16, the disc 24 and brush 16 being movable relative each other along their common axis of. rotation. The. extent of movement of the disc 24 and brush 16' toward each other, however, is limited by contact of the upper surface of the disc 24 with the bristles 20.

The device 22 is further provided with a pair of helical springs 44 for biasing the disc 24 toward engagement with the bristles 29. One spring 46 is coiled about each of the pins 36 and positioned to bear against theopin head 38 and the upper surface of the horizontal member 34.

By this arrangement, some of the bristles 20 resiliently engage the upper surface of the disc 2 4 and other bristles are at least exposed by the apertures 26 and, preferably, extend through and beyond. the apertures, to work a suitable cleaning agent into the nap or pile of the carpet. In addition, the bristies exposed by the apertures 26 establish a driving connection with the upturned marginal portions of the plate at the apertures.

An important feature of the present invention is the automatic adjustment of the device 22 to compensate for brush wear. The disc 24 is capable of floating movement on the pins 34 but, under the force of the springs 49 and the weight of the machine, the disc 24 moves into engagement with the bristles 2G, regardless of amount of prior usage, so long as the bristles are usable for effective clean- The surface-contacting portion of the disc 22 is smoothtextured and fiat. Hence, although it transmits a large portion of the machinerweight to the carpet, the disc 24 is capable of free and easy movement over the carpeted surface while, at the same time, exposes a sufficient number of bristles to effectively perform the cleaning operation.

From the foregoing, it will be apparent that the present invention has provided effective and inexpensive means for rendering smooth surface cleaning apparatus capable of cleaning carpets and the like. Cleaning is effectively accomplished because bristles are retained as the cleaning members. Also conversion can be done simply and easily, without altering the machine or changing its manner of operation in any way. Furthermore, the manner in which the driving connection is made between the brush 16 and disc 24 not only eliminates the necessity for costly tongue and slot connections between these tWo elements, 7 but also lends itself to the inclusion of the self-adiustment feature mentioned previously.

While the invention has been shown in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof;

What is claimed is:

1. Means for reducing the sliding friction between the bristles of a surface cleaning brush and a carpeted surface comprising: a plate provided with a plurality of apertures and a smooth surface, and means for removably securing said plate to said brush so that some of said bristles resiliently engage the surface opposite the smooth surface of said plate and other of said bristles are exposed by said apertures.

2. Means for reducing the sliding friction between the bristles of floor surface cleaning apparatus and carpeted surfaces, wherein said apparatus is at least partly supported on said bristles, said friction reducing means comprising a plate provided with a plurality of apertures and a smooth surface, and means for removably securing said plate to said brush so that some of said bristles resiliently engage the surface opposite the smooth surface of said plate and other of said bristles extend through said apertures.

3. Friction reducing means for, and in combination with, floor surface cleaning apparatus when said apparatus is used for cleaning carpeted surfaces, wherein said apparatus includes a multiplicity of surface contacting bristles which at least partly support the weight thereof, said friction reducing means comprising a plate provided with a plurality of apertures and a smooth surface, and means for removably securing said plate to said brush so that some of said bristles resiliently engage the surface opposite the smooth surface of said plate and other of said bristles extend through and beyond said apertures.

4. Attachable means, in combination with a surface cleaning machine having at least one motor-driven brush, for reducing the sliding friction between said brush and carpeted surfaces, wherein said brush is rotatable about a vertical axis and has a multiplicity of bristles extending toward said surface; said friction reducing means comprising: a disc provided with apertures and having a smooth, carpet-contacting surface, detachable means for fastening said disc to said brush, and means for biasing said disc toward said bristles so that some of said bristles resiliently engage the broad surface of said disc opposite its carpet-contacting surface and other of said bristles are exposed at said apertures.

5. Attachable means, in combination with a floor surface cleaning machine having at least one motor-driven brush, for adapting said machine for carpet cleaning by reducing the sliding friction between said brush and V carpeted surfaces, wherein said brush is rotatable in a plane parallel to the surface being cleaned and has a multiplicity of bristles extending toward said surface; said friction reducing means comprising: a disc provided with apertures and having a smooth, carpet-contacting surface, detachable means for fastening said disc to said brush in axially movable relationship therewith, and means associated with said disc for biasing said disc toward said bristles so that some of said bristles resiliently engage the broad surface of said disc opposite its carpetcontacting surface and other of said bristles extend through said apertures.

References Cited in the file of this patent UNITED STATES PATENTS 

